a) Field of the Invention
The present invention relates to a laser leveling system, apparatus and method particularly adapted for use in construction projects, and more particularly for construction projects where it is necessary to position a variety of components of the building structure at various locations and at specific height locations (e.g. cabinets, bookshelves, countertops, etc.).
b) Background Art
There are numerous situations in the construction industry where it is necessary to ascertain elevation locations, and also to locate various components at precise elevations. This is a task that confronts surveyors, carpenters, brick layers, and others.
The surveyor commonly uses a leveling instrument which is mounted to the top end of a tripod so as to rotate about a vertical axis while maintaining its horizontal orientation within close tolerances. Also, a conventional surveyor's transit will commonly be designed to function as a leveling instrument. These surveying instruments are usually used to place the foundation and possibly other elements of the building at the proper location and elevation. Then, as the more specific components are put into place, other locating and leveling techniques are commonly used.
A typical example is where a carpenter or cabinet maker is installing cabinets, countertops, bookshelves, etc. A common technique is to use chalk lines where a vertical elevation is established, such as measuring up a certain distance from the floor level. Then the countertops, cabinets, and other components are positioned using this chalk line as a elevation reference. The chalk line can be positioned by use of establishing one vertical location, and then using a carpenter's level to align the chalk line horizontally. Another method is simply to establish two vertical locations independently (e.g. by measuring ascertain distance up from the floor level at different locations), then making elevation marks, and stringing the chalk line between the marks.
For a number of decades, optical tooling has been used to establish locations and also elevations. Within more recent years, laser instruments have been utilized for this purpose. A search of the patent literature disclosed various concepts relating to the use of laser instruments in establishing elevations and performing other functions. These are as follows:
U.S. Pat. No. 5,566,459 (Breda) shows a laser sighting device in a housing provided with spirit levels so that the device can be leveled and aligned. There are optical elements provided so that a beam can be projected in the desired path.
U.S. Pat. No. 5,533,268 (Keightley) shows a laser sighting device that "draws" a line in both a horizontal and vertical path for use in compound surfaces such as large chemical reaction chambers. The mirror is adjusted in two planes as it rotates.
U.S. Pat. No. 5,272,834 (Key) shows a surveying device which is mounted to a tripod and in which the user can observe alight beam on the surface of surveyor's rod 14.
U.S. Pat. No. 4,718,171 (Schlemmer) shows a rotating laser beam system in which the laser beam is projected onto a staid which is provided with optical sensors 7 that provide an indication of height displayed in an output 3. This also is mounted to a tripod.
U.S. Pat. No. 3,588,249 (Studebaker) shows a right angle rotating light directing means such as a mirror or pentaprism 82. The light directing means is mounted on a rotating hollow shaft through which a laser directs light straight upward to the right angle directing means. The device is secured to an easily adjusted leveling means, and it is shown being mounted to a mobile vehicle and also to a tripod.
U.S. Pat. No. 2,661,653 (Castiglia) shows a light projecting device which is provided with a bubble level 6, that allows the device to be aligned. The device is provided with a housing that can be rotated by hand to point in any direction. The light beam is aimed at a target placed on a floor, and as the target is moved the misalignment of the floor can be measured. The device of course could be used as is the instant invention to establish alignment points on a wall or the like.
U.S. Pat. No. 4,183,667 (Denton) shows what is called a "light-ray indicator" and is supported by a universal joint, with a weight at the lower end so as to seek a plumb line.
The following five patents also relate in general in laser/optical leveling devices, and deal mostly with improvements to the leveling apparatus itself. These are the following:
U.S. Pat. No. 5,539,990 (Le) PA1 U.S. Pat. No. 5,212,889 (Lysen) PA1 U.S. Pat. No. 4,854,704 (Funazaki et al.) PA1 U.S. Pat. No. 4,679,937 (Cain et al.) PA1 U.S. Pat. No. 3,771,876 (Ljungdahl et al.)
To the best knowledge of the applicant herein, while various precision leveling instruments have been available for many, many decades (and even centuries), and although optical/laser leveling devices have also been available for decades, many tasks that are performed on a day to day basis in the construction industry where it is required to establish height elevations within reasonably close tolerances do not employ these types of instruments. Rather, the use of chalk lines, carpenter levels, tape measurers (measuring a vertical distance from a base location), etc. continue to be commonly used.
A typical instance is where a skilled carpenter or cabinet maker is installing cabinets, countertops, bookshelves and other articles. In large part, the more sophisticated leveling instruments that have been available for many decades or centuries as well as the more recent optical/laser leveling systems, which have been available for many years, carpenters and cabinet makers in large part still rely on the simpler methods as indicated above (plumb lines, leveling instruments, measuring from floor level, etc.).
Accordingly, it is an object of the present invention to provide a system, apparatus and method which incorporates a laser instrument where there is a balance of desirable features which makes it particularly convenient, "user-friendly", and efficient, and also a system where the set-up and use at various locations can be accomplished quickly and easily.
The present invention was developed to meet this need.